Abstract

Variations of renal veins are important in urology and other areas of medicine. The purpose of this study was to evaluate the prevalence and type of retroaortic left renal vein (RLRV) in patients who underwent multidetector computed tomography (MDCT). Between January 2010 and December 2019, a retrospective study was performed on 4,424 patients examined with abdominal MDCT. The prevalence and type of RLRV were determined. Age, gender, indications for imaging, and symptoms related to the variants of renal venous anatomy were recorded. MDCT images revealed RLRV in 84 of 4,424 patients (1.90% [95% cumulative incidence (CI) 1.52–2.34%]). These included 44 males (52.38%) and 40 females (47.62%). The average age of patients with RLRV was 58.29 ± 12.45 years (range, 19–88 years). RLRV types I, II, III, and IV had a distribution of 34 (0.77%), 1 (0.02%), 45 (1.02%), and 0 (0%), respectively. The extremely rare double RLRV was additionally detected in 2 cases (0.05%). Two new variations, 1 case (0.02%) with the triple RLRV and 1 case (0.02%) with the circumiliac left renal vein, were discovered. None of the patients had symptoms related to renal vein variations. Congenital anomaly of RLRV is clinically important in the investigation and exploration of retroperitoneal procedures. Therefore, preoperative imaging should be carefully considered to avoid fatal problems during surgery. To the best of our knowledge, this is the first study that reports two new variations of the left renal vein, that is, the triple RLRV and the circumiliac left renal vein.